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author | cinap_lenrek <cinap_lenrek@localhost> | 2011-05-03 11:25:13 +0000 |
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committer | cinap_lenrek <cinap_lenrek@localhost> | 2011-05-03 11:25:13 +0000 |
commit | 458120dd40db6b4df55a4e96b650e16798ef06a0 (patch) | |
tree | 8f82685be24fef97e715c6f5ca4c68d34d5074ee /sys/src/cmd/python/Doc/lib/libcfgparser.tex | |
parent | 3a742c699f6806c1145aea5149bf15de15a0afd7 (diff) |
add hg and python
Diffstat (limited to 'sys/src/cmd/python/Doc/lib/libcfgparser.tex')
-rw-r--r-- | sys/src/cmd/python/Doc/lib/libcfgparser.tex | 313 |
1 files changed, 313 insertions, 0 deletions
diff --git a/sys/src/cmd/python/Doc/lib/libcfgparser.tex b/sys/src/cmd/python/Doc/lib/libcfgparser.tex new file mode 100644 index 000000000..42a362eac --- /dev/null +++ b/sys/src/cmd/python/Doc/lib/libcfgparser.tex @@ -0,0 +1,313 @@ +\section{\module{ConfigParser} --- + Configuration file parser} + +\declaremodule{standard}{ConfigParser} +\modulesynopsis{Configuration file parser.} +\moduleauthor{Ken Manheimer}{klm@zope.com} +\moduleauthor{Barry Warsaw}{bwarsaw@python.org} +\moduleauthor{Eric S. Raymond}{esr@thyrsus.com} +\sectionauthor{Christopher G. Petrilli}{petrilli@amber.org} + +This module defines the class \class{ConfigParser}. +\indexii{.ini}{file}\indexii{configuration}{file}\index{ini file} +\index{Windows ini file} +The \class{ConfigParser} class implements a basic configuration file +parser language which provides a structure similar to what you would +find on Microsoft Windows INI files. You can use this to write Python +programs which can be customized by end users easily. + +\begin{notice}[warning] + This library does \emph{not} interpret or write the value-type + prefixes used in the Windows Registry extended version of INI syntax. +\end{notice} + +The configuration file consists of sections, led by a +\samp{[section]} header and followed by \samp{name: value} entries, +with continuations in the style of \rfc{822}; \samp{name=value} is +also accepted. Note that leading whitespace is removed from values. +The optional values can contain format strings which refer to other +values in the same section, or values in a special +\code{DEFAULT} section. Additional defaults can be provided on +initialization and retrieval. Lines beginning with \character{\#} or +\character{;} are ignored and may be used to provide comments. + +For example: + +\begin{verbatim} +[My Section] +foodir: %(dir)s/whatever +dir=frob +\end{verbatim} + +would resolve the \samp{\%(dir)s} to the value of +\samp{dir} (\samp{frob} in this case). All reference expansions are +done on demand. + +Default values can be specified by passing them into the +\class{ConfigParser} constructor as a dictionary. Additional defaults +may be passed into the \method{get()} method which will override all +others. + +\begin{classdesc}{RawConfigParser}{\optional{defaults}} +The basic configuration object. When \var{defaults} is given, it is +initialized into the dictionary of intrinsic defaults. This class +does not support the magical interpolation behavior. +\versionadded{2.3} +\end{classdesc} + +\begin{classdesc}{ConfigParser}{\optional{defaults}} +Derived class of \class{RawConfigParser} that implements the magical +interpolation feature and adds optional arguments to the \method{get()} +and \method{items()} methods. The values in \var{defaults} must be +appropriate for the \samp{\%()s} string interpolation. Note that +\var{__name__} is an intrinsic default; its value is the section name, +and will override any value provided in \var{defaults}. + +All option names used in interpolation will be passed through the +\method{optionxform()} method just like any other option name +reference. For example, using the default implementation of +\method{optionxform()} (which converts option names to lower case), +the values \samp{foo \%(bar)s} and \samp{foo \%(BAR)s} are +equivalent. +\end{classdesc} + +\begin{classdesc}{SafeConfigParser}{\optional{defaults}} +Derived class of \class{ConfigParser} that implements a more-sane +variant of the magical interpolation feature. This implementation is +more predictable as well. +% XXX Need to explain what's safer/more predictable about it. +New applications should prefer this version if they don't need to be +compatible with older versions of Python. +\versionadded{2.3} +\end{classdesc} + +\begin{excdesc}{NoSectionError} +Exception raised when a specified section is not found. +\end{excdesc} + +\begin{excdesc}{DuplicateSectionError} +Exception raised if \method{add_section()} is called with the name of +a section that is already present. +\end{excdesc} + +\begin{excdesc}{NoOptionError} +Exception raised when a specified option is not found in the specified +section. +\end{excdesc} + +\begin{excdesc}{InterpolationError} +Base class for exceptions raised when problems occur performing string +interpolation. +\end{excdesc} + +\begin{excdesc}{InterpolationDepthError} +Exception raised when string interpolation cannot be completed because +the number of iterations exceeds \constant{MAX_INTERPOLATION_DEPTH}. +Subclass of \exception{InterpolationError}. +\end{excdesc} + +\begin{excdesc}{InterpolationMissingOptionError} +Exception raised when an option referenced from a value does not exist. +Subclass of \exception{InterpolationError}. +\versionadded{2.3} +\end{excdesc} + +\begin{excdesc}{InterpolationSyntaxError} +Exception raised when the source text into which substitutions are +made does not conform to the required syntax. +Subclass of \exception{InterpolationError}. +\versionadded{2.3} +\end{excdesc} + +\begin{excdesc}{MissingSectionHeaderError} +Exception raised when attempting to parse a file which has no section +headers. +\end{excdesc} + +\begin{excdesc}{ParsingError} +Exception raised when errors occur attempting to parse a file. +\end{excdesc} + +\begin{datadesc}{MAX_INTERPOLATION_DEPTH} +The maximum depth for recursive interpolation for \method{get()} when +the \var{raw} parameter is false. This is relevant only for the +\class{ConfigParser} class. +\end{datadesc} + + +\begin{seealso} + \seemodule{shlex}{Support for a creating \UNIX{} shell-like + mini-languages which can be used as an alternate + format for application configuration files.} +\end{seealso} + + +\subsection{RawConfigParser Objects \label{RawConfigParser-objects}} + +\class{RawConfigParser} instances have the following methods: + +\begin{methoddesc}{defaults}{} +Return a dictionary containing the instance-wide defaults. +\end{methoddesc} + +\begin{methoddesc}{sections}{} +Return a list of the sections available; \code{DEFAULT} is not +included in the list. +\end{methoddesc} + +\begin{methoddesc}{add_section}{section} +Add a section named \var{section} to the instance. If a section by +the given name already exists, \exception{DuplicateSectionError} is +raised. +\end{methoddesc} + +\begin{methoddesc}{has_section}{section} +Indicates whether the named section is present in the +configuration. The \code{DEFAULT} section is not acknowledged. +\end{methoddesc} + +\begin{methoddesc}{options}{section} +Returns a list of options available in the specified \var{section}. +\end{methoddesc} + +\begin{methoddesc}{has_option}{section, option} +If the given section exists, and contains the given option, +return \constant{True}; otherwise return \constant{False}. +\versionadded{1.6} +\end{methoddesc} + +\begin{methoddesc}{read}{filenames} +Attempt to read and parse a list of filenames, returning a list of filenames +which were successfully parsed. If \var{filenames} is a string or +Unicode string, it is treated as a single filename. +If a file named in \var{filenames} cannot be opened, that file will be +ignored. This is designed so that you can specify a list of potential +configuration file locations (for example, the current directory, the +user's home directory, and some system-wide directory), and all +existing configuration files in the list will be read. If none of the +named files exist, the \class{ConfigParser} instance will contain an +empty dataset. An application which requires initial values to be +loaded from a file should load the required file or files using +\method{readfp()} before calling \method{read()} for any optional +files: + +\begin{verbatim} +import ConfigParser, os + +config = ConfigParser.ConfigParser() +config.readfp(open('defaults.cfg')) +config.read(['site.cfg', os.path.expanduser('~/.myapp.cfg')]) +\end{verbatim} +\versionchanged[Returns list of successfully parsed filenames]{2.4} +\end{methoddesc} + +\begin{methoddesc}{readfp}{fp\optional{, filename}} +Read and parse configuration data from the file or file-like object in +\var{fp} (only the \method{readline()} method is used). If +\var{filename} is omitted and \var{fp} has a \member{name} attribute, +that is used for \var{filename}; the default is \samp{<???>}. +\end{methoddesc} + +\begin{methoddesc}{get}{section, option} +Get an \var{option} value for the named \var{section}. +\end{methoddesc} + +\begin{methoddesc}{getint}{section, option} +A convenience method which coerces the \var{option} in the specified +\var{section} to an integer. +\end{methoddesc} + +\begin{methoddesc}{getfloat}{section, option} +A convenience method which coerces the \var{option} in the specified +\var{section} to a floating point number. +\end{methoddesc} + +\begin{methoddesc}{getboolean}{section, option} +A convenience method which coerces the \var{option} in the specified +\var{section} to a Boolean value. Note that the accepted values +for the option are \code{"1"}, \code{"yes"}, \code{"true"}, and \code{"on"}, +which cause this method to return \code{True}, and \code{"0"}, \code{"no"}, +\code{"false"}, and \code{"off"}, which cause it to return \code{False}. These +string values are checked in a case-insensitive manner. Any other value will +cause it to raise \exception{ValueError}. +\end{methoddesc} + +\begin{methoddesc}{items}{section} +Return a list of \code{(\var{name}, \var{value})} pairs for each +option in the given \var{section}. +\end{methoddesc} + +\begin{methoddesc}{set}{section, option, value} +If the given section exists, set the given option to the specified +value; otherwise raise \exception{NoSectionError}. While it is +possible to use \class{RawConfigParser} (or \class{ConfigParser} with +\var{raw} parameters set to true) for \emph{internal} storage of +non-string values, full functionality (including interpolation and +output to files) can only be achieved using string values. +\versionadded{1.6} +\end{methoddesc} + +\begin{methoddesc}{write}{fileobject} +Write a representation of the configuration to the specified file +object. This representation can be parsed by a future \method{read()} +call. +\versionadded{1.6} +\end{methoddesc} + +\begin{methoddesc}{remove_option}{section, option} +Remove the specified \var{option} from the specified \var{section}. +If the section does not exist, raise \exception{NoSectionError}. +If the option existed to be removed, return \constant{True}; +otherwise return \constant{False}. +\versionadded{1.6} +\end{methoddesc} + +\begin{methoddesc}{remove_section}{section} +Remove the specified \var{section} from the configuration. +If the section in fact existed, return \code{True}. +Otherwise return \code{False}. +\end{methoddesc} + +\begin{methoddesc}{optionxform}{option} +Transforms the option name \var{option} as found in an input file or +as passed in by client code to the form that should be used in the +internal structures. The default implementation returns a lower-case +version of \var{option}; subclasses may override this or client code +can set an attribute of this name on instances to affect this +behavior. Setting this to \function{str()}, for example, would make +option names case sensitive. +\end{methoddesc} + + +\subsection{ConfigParser Objects \label{ConfigParser-objects}} + +The \class{ConfigParser} class extends some methods of the +\class{RawConfigParser} interface, adding some optional arguments. + +\begin{methoddesc}{get}{section, option\optional{, raw\optional{, vars}}} +Get an \var{option} value for the named \var{section}. All the +\character{\%} interpolations are expanded in the return values, based +on the defaults passed into the constructor, as well as the options +\var{vars} provided, unless the \var{raw} argument is true. +\end{methoddesc} + +\begin{methoddesc}{items}{section\optional{, raw\optional{, vars}}} +Return a list of \code{(\var{name}, \var{value})} pairs for each +option in the given \var{section}. Optional arguments have the +same meaning as for the \method{get()} method. +\versionadded{2.3} +\end{methoddesc} + + +\subsection{SafeConfigParser Objects \label{SafeConfigParser-objects}} + +The \class{SafeConfigParser} class implements the same extended +interface as \class{ConfigParser}, with the following addition: + +\begin{methoddesc}{set}{section, option, value} +If the given section exists, set the given option to the specified +value; otherwise raise \exception{NoSectionError}. \var{value} must +be a string (\class{str} or \class{unicode}); if not, +\exception{TypeError} is raised. +\versionadded{2.4} +\end{methoddesc} |